Guo-Li Qu, Jian-Rong Dai, Yi-An Wang, Yun-Tian Xing, Xue-Hui Shen, Wei Wang, You-Sheng Liang
Jiangsu Institute of Parasitic Diseases, Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasites and Vector Control Technology, Wuxi 214064, China.
Dantu District Center for Disease Control and Prevention, Zhenjiang City, Jiangsu Province, China.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi. 2016 Oct 20;28(5):490-496. doi: 10.16250/j.32.1374.2016169.
To investigate the survival of Schistosoma japonicum eggs in goat feces in natural marshlands and the factors affecting its survival, so as to provide evidences for understanding of the role of eggs in goat feces in the transmission of schistosomiasis and the development of the interventions pertaining to disease control and elimination.
The goat animals of schistosomiasis japonica were modeled in laboratory, and the feces of infected goat were collected. In laboratory, the effects of environmental temperature and water content in goat feces on egg hatching were evaluated, and in the field, the effect of duration of goat feces on marshland on egg hatching and the effect of direct sunshine on egg survival were evaluated.
At 25°C in laboratory, the hatching rate of eggs in goat feces washigh-positively correlated with the water content in goat feces ( = 0.87). If the water content reduced to 7.6% in goat feces, the eggs in goat feces lost the ability to hatch. Under the same water content in goat feces, the hatching rate of eggs gradually decreased with the extension of the duration of exposure of goat feces to -5 °C, which reduced to 0 following 5 h exposure. At 5, 15 and 25 °C, the hatching rates of eggs gradually decreased with the extension of the duration of exposure of goat feces, and themiracidium hatching ratesof eggs were 2.3%, 5% and 0.9% respectively following the exposure for 52 d. At 35°C, the hatching rate of eggs gradually decreased with the extension of the duration of exposure, which reduced to 0 following 13 d exposure. In winter (-2-10 °C), the hatching rate of eggs gradually decreased with the extension of the duration of exposure of goat feces on marshlands, which reduced to 0 after 21 d of exposure, and in spring (16-19 °C), the hatching rate of eggs gradually decreased with the extension of the duration of exposure of goat feces on marshlands, which reduced to 0.9% after 5 d of exposure. At the same time point on the same marshland, the hatching rate of eggs in goat feces exposed to marshlands with direct sunshine was lower than that without direct sunshine.
The survival of eggs in goat feces is associated with environmental temperature and water content (humidity) in goat feces, and the temperature and humidity are major natural factors affecting egg hatching.
研究日本血吸虫卵在天然沼泽地山羊粪便中的存活情况及其影响因素，为了解山羊粪便中虫卵在血吸虫病传播中的作用及制定疾病控制与消除干预措施提供依据。
在实验室对日本血吸虫病山羊进行建模，并收集感染山羊的粪便。在实验室评估环境温度和山羊粪便含水量对虫卵孵化的影响，在现场评估山羊粪便在沼泽地放置时间对虫卵孵化的影响以及阳光直射对虫卵存活的影响。
在实验室25℃条件下，山羊粪便中虫卵的孵化率与山羊粪便含水量呈高度正相关（r = 0.87）。当山羊粪便含水量降至7.6%时，粪便中的虫卵失去孵化能力。在山羊粪便含水量相同的情况下，随着山羊粪便暴露于-5℃时间的延长，虫卵孵化率逐渐降低，暴露5小时后降至0。在5℃、15℃和25℃时，随着山羊粪便暴露时间的延长，虫卵孵化率逐渐降低，暴露52天后虫卵的毛蚴孵化率分别为2.3%、5%和0.9%。在35℃时，随着暴露时间的延长，虫卵孵化率逐渐降低，暴露13天后降至0。冬季（-2-10℃），随着山羊粪便在沼泽地暴露时间的延长，虫卵孵化率逐渐降低，暴露21天后降至0，春季（16-19℃），随着山羊粪便在沼泽地暴露时间的延长，虫卵孵化率逐渐降低，暴露5天后降至0.9%。在同一沼泽地的同一时间点，暴露于阳光直射的沼泽地的山羊粪便中虫卵的孵化率低于无阳光直射的情况。
山羊粪便中虫卵的存活与环境温度和山羊粪便含水量（湿度）有关，温度和湿度是影响虫卵孵化的主要自然因素。
